* {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
  }
  
  body {
    background: #222;
    display: flex;
    justify-content: center;
    align-items: center;
    height: 100vh;
  }
  
  .app {
    width: 100%;
    max-width: 390px;
    
    height: 100dvh;
    max-height: 844px; 

    background: white;
  
    display: flex;
    flex-direction: column;
  
    border-radius: 28px;
    overflow: hidden;
  
    box-shadow: 0 20px 60px rgba(0,0,0,0.6);
  }
  
  .app-header {
    background: #4a90e2;
    color: white;
    padding: 16px;
    text-align: center;
    font-size: 18px;
    font-weight: 600;
    flex-shrink: 0;
  }
  
  #main-view {
    position: relative;
    flex: 1;
    background: white;
  
    display: flex;
    justify-content: center;
    align-items: center;
  
    overflow: hidden;
  }

  #setting-button {
    position: absolute;
    top: 16px;
    right: 16px;
  
    z-index: 20; /* make sure it's above camera */
    cursor: pointer;
  }
  
  #setting-button img {
    width: 32px; /* adjust size as needed */
    height: 32px;
  }
  
  #camera-placeholder {
    text-align: center;
    color: #333;
    padding: 20px;
    z-index: 2;
  }
  
  #camera-placeholder button {
    margin-top: 12px;
    padding: 12px 16px;
    border: none;
    border-radius: 8px;
    background: #4a90e2;
    color: white;
    font-size: 16px;
  }

  #camera-placeholder h3{
    padding-top: 10px;
  }
  
  #camera-feed {
    position: absolute;
    top: 0;
    left: 0;
  
    width: 100%;
    height: 100%;
  
    object-fit: cover;
    display: none;
  
    z-index: 1;
  }

  video {
    cursor: pointer;
  }

  #camera-overlay {
    display: none;
    position: absolute;
    top: 16px;
    left: 50%;
    transform: translateX(-50%);
    z-index: 10;
    color: white;
    font-size: 20px;
    font-weight: bold;
    text-shadow: 0 0 6px rgba(0,0,0,0.7);
    pointer-events: none;
  }

  #flash-overlay {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: white;
    opacity: 0;
    pointer-events: none;
    z-index: 50;
    transition: opacity 0.1s ease-in-out;
  }

  #settings-panel {
    position: absolute;
    bottom: 20px;
    left: 50%;
    transform: translateX(-50%);
  
    height: 90%;
    width: 85%;
    max-width: 320px;
  
    background: rgba(74,144,242, 0.85);
    color: white;
  
    padding: 16px;
    border-radius: 16px;
  
    z-index: 100;
  
    display: none; /* hidden by default */
  
    box-shadow: 0 10px 30px rgba(0,0,0,0.5);
  }
  
  #settings-panel h2 {
    margin-bottom: 10px;
    font-size: 18px;
    text-align: center;
  }

  #settings-panel label {
    display: block;
    font-size: 18px;
    margin-bottom: 12px;
  }
  
  #settings-panel input[type="checkbox"] {
    margin-left: 10px;
  }

  .setting-row {
    height: 25%;
    padding: 14px;
    border-radius: 12px;
    background: rgba(255,255,255,0.15);
    color: white;
  }
  
  .setting-title {
    font-size: 16px;
    margin-bottom: 8px;
  }
  
  /* clickable split area */
  .tap-area {
    width: 100%;
    height: 75%;
    display: flex;
  }

  .tap-area::before {
    border-right: 2px solid white;
  }
  
  #text-size-area::before,
  #tts-volume-area::before {
    content: "−";
    flex: 1;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 24px;
    color: white;
    opacity: 0.8;
  }
  
  #text-size-area::after,
  #tts-volume-area::after {
    content: "+";
    flex: 1;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 24px;
    color: white;
    opacity: 0.8;
  }
  
  /* disabled state */
  .tap-area.disabled {
    opacity: 0.4;
    pointer-events: none;
  }
  
  /* whole-row toggle */
  .setting-row.clickable {
    cursor: pointer;
  }

  #close-settings {
    margin-top: 10px;
    padding: 10px;
    border: none;
    border-radius: 8px;
    background: white;
    color: #4a90e2;
    width: 100%;
  }
  
  @media (max-width: 750px) {
    body {
      background: white;
      display: block;
      height: auto;
    }
  
    .app {
      width: 100%;
      max-width: 650px;
        
      height: 100dvh;
      max-height: 844px; 
      border-radius: 0;
      box-shadow: none;
    }
  }